News

GIST research team finds potential for improved sleep in humans
Preliminary trial of 40 people found a 26% reduction in insomnia symptoms
No significant differences were found in objective

Simply shining near-infrared light on the head before bedtime may increase a substance in the brain that promotes sleep and could help reduce symptoms of insomnia, a new study suggests.

A research team led by Professors Tae Kim and Jaegwan Kim of the Department of Biomedical Engineering at Gwangju Institute of Science and Technology (GIST) reported on the 23rd that they have identified potential effects of transcranial photobiomodulation (tPBM), a technique that uses near-infrared light on the head, on the brain's sleep-regulation processes.

The researchers focused on adenosine, a substance that accumulates in the brain the longer a person stays awake and helps promote sleepiness. The team hypothesized that near-infrared light may stimulate the activity of mitochondria, the "powerhouses" of brain cells, increasing adenosine triphosphate (ATP), the cells' main energy source. As ATP is broken down, it may subsequently increase levels of adenosine.

In experiments using mice, shining near-infrared light on the brain reduced the amount of time the animals remained awake and increased their total sleep time. In particular, the mice showed increased brain-wave activity associated with deep sleep, along with higher levels of adenosine in the brain. These effects lasted for up to three hours after the light stimulation ended.

To determine whether similar effects could be observed in humans, the researchers conducted a preliminary clinical trial involving 40 adults experiencing symptoms of insomnia. Participants were divided into two groups: one used a device that emitted near-infrared light, while the other used a control device. Both groups wore the device on their heads before bedtime for one week.

The near-infrared light group reported improvements in perceived insomnia symptoms and sleep quality. Their Insomnia Severity Index (ISI) scores decreased by 26%, while their Pittsburgh Sleep Quality Index (PSQI) scores, which measure sleep quality, decreased by 29.6%.

However, the findings do not establish that near-infrared light is an effective treatment for insomnia. Objective sleep measurements recorded using wrist-worn devices showed no significant differences between the two groups. In addition, the researchers were unable to directly confirm that adenosine levels actually increased in the human brain.

The research team plans to conduct larger studies to further evaluate the potential sleep-improving effects of near-infrared light and assess its long-term safety.

The findings were published online on September 15 in the international journal Molecular Psychiatry.

Source: 한국일보 (https://www.hankookilbo.com/news/article/A2026092309010002009)